A quarter of patients with chronic obstructive pulmonary disease (COPD) in the United States have no history of smoking. The occupational contribution to development of COPD is significant. Endotoxin is a ubiquitous and poorly recognized environmental and occupational exposure that may cause non-tobacco related COPD. In recent studies, chronic inhalational endotoxin has been associated with the development of obstructive lung disease in both humans and murine models. Despite the importance of endotoxin related lung disease, it has not been well studied. The primary objective of this study is to investigate the biology underlying the development of chronic obstructive lung disease due to long term endotoxin exposure. We hypothesize that specific genes and genes grouped by function or interaction play a role in the development of endotoxin related lung disease. To test this hypothesis, we will select candidate single nucleotide polymorphisms (SNPs) and associated genes by integrating high density customized genotyping data in an exposure-naove newly hired cohort of cotton textile workers with gene expression data in a phenotypically validated murine model of chronic endotoxin exposure. Wewill also use contextual information such as functional annotation and protein-protein interactions to re-rank SNPs that fail to reach genome wide significance. Candidate regions will then be tested in a chronically exposed long term cohort of cotton textile workers. Validated regions will then be annotated for putative biological function, and an interaction analysis will b performed on all validated regions to infer disease causing mechanisms underlying chronic inhaled endotoxin and obstructive lung disease. As part of the research training program, the principle investigator will complete a Master of Public Health with a concentration in Quantitative Methods in order to acquire the necessary epidemiology and biostatistics skills, as well as relevant bioinformatics tools. This research project will be performed under the mentorship of an established investigator in genetic epidemiology who has studied endotoxin-related lung disease for the past 3 decades.